Window structure



Nov. 16, 1965 XAVIER FRANZ LElslBAcl-l 3,217,454

M so KNOWN As XAVER LEISIBACH WINDOW 'STRUCTURE Filed OCT.. 21, 1964 2Sheets-Sheet 1 Fim f (3U AGENT Nov. 16, 1965 XAVIER FRANZ LEISIBACH ALSOKNOWN AS XAVER LEISIBACH WINDOW STRUCTURE Filed Oct. 2l, 1964 2Sheets-Sheet 2 MQ. 12o. *l5

XAVIER FRANZ LE/S/BACH INVENTOR AGENT,

United States Patent O 3,217,454 WINDW STRUCTURE Xavier Franz Leisibach,also known as Xaver Leisibach, Lerchenhain-Meggen, Lucerne, SwitzerlandFiled Oct. 21, 1964, Ser. No. 405,628 Claims priority, applicationGermany, Feb. 7, 1961,

1 Claim. `(Cl. 52-398) My present invention relates to window structuresand, more particularly, to a window construction in which two or morepanes are held in a common sash, as described in my copendingapplication Ser. No. 171,365, filed February 6, 1962, of which mypresent application is a continuation-in-part.

In this copending application I have pointed out that changes inatmospheric temperature and humidity, generally accompanied by atemperature differential on both sides of the window so that the twopanes are often eX- posed to different ambient conditions, subjectWindow structures of this type to severe tests and tax their mechanicalstability and their resistance to moisture penetration. It was diflicultin the past to assemble dualor multiple-pane windows in such manner thatthe space between adjacent panes was sufficiently airtight to preventthe generation of convection currents` or the deposition of moisture onthe inner glass surfaces. In many instances, therefore, it was necessaryto dispose a drying agent, such as silica gel, in the intervening spaceand/ or to provide special passages for flushing that space with a drygas such as nitrogen.

One of the principal reasons for the aforementioned difficulties derivesfrom the fact that metallic frame elements are good thermal conductorsso that, at low temperatures, the vapors unavoidably present between thepanes will tend to condense, whereas nonmetallic frame members aregenerally composed of wood and are so highly porous that it is difficultto prevent penetration of moisture into this space.

To avoid these difficulties it has been proposed hitherto to providedouble-window structures with elastomeric glazing strips which arepreformed and are inserted into grooves in the sash and generally extendsomewhat from these grooves to define channels receiving the panes. Inone construction of this type, a tight seal is ensured by seating thepanes on a ledge of the glazing strip abutting a shoulder or supportridge of the sash directly below the pane and thereafter forcing anotherportion of the glazing strip into a channel in the sash so that thestrip bears upon a marginal portion of the pane. In other arrangements,this portion of the strip is detached from that portion upon which thepane rests and is so dimensioned that, while it is forced into thegroove in the sash, if bears resiliently upon the panes. In stillfurther known constructions of this general type, the pane does not restupon the ledge of the glazing strip but instead is frictionallysupported by two portions of the strip engaging opposite faces of eachpane.

While such arrangements overcome some of the more significantdisadvantages mentioned above, especially with regard to theconductivity of the sash in contact with the panes, they introduce anentirely new problem. It is well known that the elastomeric sealingstrips of this nature tend to loose their resiliency at an early stageand to stilfen so that, in spite of the fact that the sealing strip mayhave been bearing originally upon the panes, their rigidity subsequentlyeliminates any such resilient cornpression and the required seal. It is,therefore, a prin- ICC cipal object of my present invention to providean improved window structure of the type set forth in which all of theaforementioned drawbacks are avoided.

A more specic object of this invention is to provide a window structuremaking use of a sealing strip whereby stiffening of the strip will notimpose the great diculties encountered heretofore.

In accordance with the present invention I provide, within a sash whichmay be of any conventional type (e.g., sliding, swinging or stationary),a spacing frame of low thermal conductivity engaged on opposite sides bya pair of spaced window panes, the frame constituting the sealing orglazing strip mentioned above and being mounted in a sash consisting ofa light, nonporous material such as lightweight metal (e.g., aluminum)having means for holding both the panes and the glazing strip in closecontact with one another. The invention resides in undercutting at leastone of the grooves of the sash for reeciving an outer portion of theglazing strip which may be integral or formed from a plurality ofseparate portions, this undercut groove having a constriction past whichan enlarged bead of the glazing strip can be forced.

According to a principal feature of this invention, the undercut portionof the groove is of generally circular cross-section with a surface ofthe sash underlying the pane being substantially tangential to thecylindrical surface forming the interior wall of the undercut region.The corresponding portion of the glazing strip is complementarily shapedso that its bead has a generally cylindrical configuration. Thesefeatures of the invention afford two main advantages over prior-artstructures utilizing glazing strips received within a groove in thesash: On the one hand, the undercut nature of the groove and enlargedbead adapted to be forced through the constricted opening in to thegroove precludes undesirable and spontaneous movement of the glazingstrip out of the sash upon thermal contraction and expansion of thelatter as frequently occurs with conventional glazing strips. It may benoted, parenthetically, that it has been proposed hitherto to provide atleast the outer portions of such glazing strips with a multiplicity offormations for increasing the frictional interengagement betweenjuxtaposed surfaces of the sash and glazing strip; these have not beensuccessful, however. On the other hand, even stiffening or some degreeof shrinking of the glazing strip cannot decrease the sealing pressurewith which the strip bears against the pane; the sealing strip has apane-engaging edge which, in effect, constitutes the load element of alever fulcrumed about the axis of the cylindrical groove and the bead.

According to a more specific feature of the present invention, theglazing strip is provided with an abutment laterally spaced from thecylindrical groove away from the pane and engageable by the sash forpreventing it from swivelling about the aforementioned axis away fromthe pane. Moreover, the glazing strip is, according to the invention,provided with a lever arm underlying the pane and tending to swivel theglazing strip about the axis so that its sealing edge engages a marginalportion of the pane with a force determined by the weight of the pane.Thus, even after some stilfening of the glazing strip, the weight of thepane upon the lever arm of the lower glazing strip will maintain asealing engagement; the abutment serves to main-tain the remainingstrips about the periphery of the pane in engagement therewith.

Still another feature of the present invention resides in the provisionof an intermediate portion of the glazingstrip means disposed betweenthe panes and which, in

tionally used as heat insulators.

profile, converges'toward the periphery thereof; the intermediateglazing portion has a relatively wide head whose edges bear uponrelatively narrow marginal portions of the pane. This intermediateportion of the glazing-strip means is supported at its nar-row shankoutwardly from this head so that the head is, to some degree, shiftablelaterally of the panes during thermal changes of the div'mensions of thewindow structure.

Still another feature of the instant invention resides in the provisionof at least one inner ridge on the sash between the panes and extendinginwardly beyond the periphery of the panes while being straddled by theframe 'or glazing strip. The shank of the intermediate portion of theglazing strip can then `be mounted upon this ridge in such manner as tobe defiectable laterally thereof. The interengagement of the glazingstrip with the sash may be supplemented by the provision of an adhesive,preferably of elastomeric material, which can be introduced between theengaging edges of the head of the `intermediate portion and theperiphery of the panes along ythe shank.

Suitable strip materials of low thermal conductivity include syntheticand natural rubbers, e.g., porous or microporous rubber, along `withother substances conven- The sash, in turn, may be composed of extrudedprofiles of metal, preferably aluminum, integrally formed with thenecessary ridges or grooves to accommodate the panes and the sealingstrip. It will be understood that, even with strips of relatively highporosity, the penetration of moisture into the space between the paneswill be prevented by the intervening layer of adhesive.

The above and other objects, features and advantages of the presentinvention will become more readily aplparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. l is a front-elevational view of a window strucrune1 of the type towhich the present invention is applica e;

FIG. 2 is an enlarged cross-sectional view taken along the line II--IIof FIG. 1; and

FIGS. 3a, 3b and 3c are fragmentary sectional views drawn to the scaleof FIG. 2, representing different modiiications of that part of FIG. 2encompassed within the area III thereof.

The window shown in FIG. 1 comprises a pair of slidable sashes 2, 2,within an outer frame 1 which is representative of any conventionalembrasure or other support for such, sashes. The two sashes 2, 2 areidentical except for a conventional Outrigger strip 20 on the former forpreventing the flow of airhetween the sashes. Only t-he sash 2 and itsassociated elements will be described in detail with the identical partshaving primed reference numerals in sash 2.

As illustrated in FIG. 2, the sash 2 carries a pair of panes 3 spacedapart by a glazing-strip means 4, 5 of rubber or similar, preferablyelastomeric, thermally insulating material. The glazing strip means thusincludes an intermediate portion or inner frame 4 and a pair of outerportions S, 5a. The latter are provided with respective beads 1'2, 12aof generally cylindrical configuration which are received in thecomplementary (i.e., cylindrical) undercut grooves y13, extending allaround the inner periphery of the sash on either side of the pair ofpanes 3. These grooves open via the constrictions 113 at the surfaces213 of the sash underlying pane 3, the constrictions having a width lessthan the diameter of the beads 112, 12a.

The space -6 between the panes 3 is shielded against the atmosphere byadhesive layers 15 (e.g., of rubber cement) which likewise extend alongthe entire inner periphery of the sash and help secure it to theintermediate portion 4 of the glazing-strip means and the panes.

As previously indicated, the intermediate portion 4 has an enlarged head104 and converges outwardly in the direction of the peripheries of thepanes to form a shank 204 which is received between a pair of Iridges 10integrally formed on the sash and extending inwardly therebeyond. Thehead 104 is thus resiliently deectable upon thermal alteration of thedimensions of the sash. A packing strip 14a, independent of strip 5a,underlies the right-hand pane 3 (FIG. 2) to support the latter while theother pane is carried by a lever arm 14 integral with glazing stripportion 5 whose load arm includes an edge 105 urged into contact with amarginal portion of the respective pane by t-he weight thereof, strip 5being fulcrumed upon the axis of the cylinders 112, 13. Abutment ledges205, v20551, outwardly of the panes, are provided on the outer portions`5, 5a flanking the vbeads y12, 12a for engagement with the surface 213to prevent the glazing strip portions 5 and 5a from being deflectedoutwardly about their Vrespective axes.

The sash 2 is provided with several rollers 8 (only one shown) whichride in a horizontal groove of a flange 7 on the bottom of frame 1whereby he sashes 2 and 2 may be rolled back and forth in theconventional manner. Packing strips 9 of felt or the like are interposedbetween the inner faces of the U-proiile of the sash and the T-shapedflange 7. This construction, known per se, is shown merely for the sakeof completeness and is representative of any conventional sash mounting.

In FIG. 3a I show a construction otherwise `identical with thatdescribed in connection wit-h FIG. 2 except that the sash 2a has asingle ridge 10a matingly received within a peripheral groove 304a inthe shank 204a of the intermediate portion or inner frame 4a whose head10i4a has edges bearing upon the marginal portions of the panes. Again,-this enlarged head is deflectable, as indicated above, the adhesivelayers 15 not materially impeding such deflection.

In a further .rnodicatiom` shown in FIG. 3b, the sash I2b has arelatively wide ridge or rib 10b overlain by the intermediate portion4b. Studs 17 (only one shown) rise from the rib 10b at spaced locationstherealong and are imbedded in the shank of the intermediate portion orinner frame 4b to lock it into position with its enlarged head bearingagainst the panes.

In, FIG. 3c, I have shown the sash 2c formed wit-h an inner peripheralgroove 11 accommodating the outer edge of the shank of intermediateportion or inne-r frame 4c, which is here illustrated to be of T-shapedprofile.

Structural modifications of the space arrangements described andillustrated are, of course, possible without departing from the spiritand scope of my linvention as defined in the appended claim.

I claim:

In a window, in combination, a profiled metallic sash formed with atleast one inner ridge extending over its entire circumference, an innerframe of atleast partly complementary profile matingly engaging saidsash, said frame consisting of a material of low thermal conductivity, apa-ir of panes held in said sash and contacting said frame from oppositesides, and a pair of sealing strips independent of said frame anchoredin said sash, said strips resiliently bearing upon the outer surfaces ofsaid panes over a marginal zone extending all around their circumferencewhereby said panes are urged toward said frame; said ridge projectinginto the space between said panes and being received in a mating grooveof said frame; said frame registering with substantially all of saidmarginal zone and constituting the only structural member bridging saidpanes, at least one of said strips having a generally cylindrical footreceived within a complementary recess in said sash, said one of saidstrips having an integral lateral flange intermediate said marginal zoneand said sash while underlying the corresponding pane .for urging therespective strip against the pane.

(References on following page) 5 References Cited by the Examiner3,026,582

UNITED STATES PATENTS 4/1940 Axe 20-565 X 5/ 1941 *Hunter 189-78 56/,1942 Axe 189-64 .653,714 3/1959 Haas 20-565 3/1962 Haas ,20-56.5 X

6 y3/1962 Bayer 20-565 6/'1962 Fengler 20--56.4 X 1/1963 Gall 189- 76 XFOREIGN PATENTS 5/1951 Great Britain.

CHARLES E. OCONNELL, Primary Examiner.

